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Concept

Basalte

Publications associées (29)

Well-Defined Ti Surface Sites in Ziegler-Natta Pre-Catalysts from 47/49Ti Solid-State Nuclear Magnetic Resonance Spectroscopy

Pierrick Berruyer

Treatment of Ziegler-Natta (ZN) catalysts with BCl3 improves their activity by increasing the number of active sites. Here we show how Ti-47/49 solid-state nuclear magnetic resonance (NMR) spectroscopy enables us to understand the electronic structure of t ...

Amer Chemical Soc2024

Composition and Pressure Effects on Partitioning of Ferrous Iron in Iron-Rich Lower Mantle Heterogeneities

Marco Cantoni, Philippe Gillet, James Badro, Farhang Nabiei, Susannah McGregor Dorfman, Charles-Edouard Boukaré

Both seismic observations of dense low shear velocity regions and models of magma ocean crystallization and mantle dynamics support enrichment of iron in Earth’s lowermost mantle. Physical properties of iron-rich lower mantle heterogeneities in the modern ...

2021

The effect of alkali hydroxides and equilibration time on Al uptake by calcium silicate hydrates (C-S-H)

Sonya Barzgar

Cement production accounts for approximately 8% of man-made CO2 emissions. Lowering these CO2 emissions is currently one of the most important and urgent research topics within the cement community. To reduce these emissions, the Portland cement (PC) is pa ...

EPFL2021

Stability of hydrate assemblages and properties of cementitious systems with higher alumina content

Natechanok Chitvoranund

Two low CO2 cement systems are investigated: one made with the use of supplementary cementitious materi-als (SCMs) (metakaolin and limestone) and the other an alternative binder, calcium sulfoaluminate cement (CSA). These two low CO2 cements contain a simi ...

EPFL2021

Effects of composition and pressure on electronic states of iron in bridgmanite

Philippe Gillet, Arnaud Magrez, Susannah McGregor Dorfman

Electronic states of iron in the lower mantle's dominant mineral, (Mg,Fe,Al)(Fe,Al,Si)O-3 bridgmanite, control physical properties of the mantle including density, elasticity, and electrical and thermal conductivity. However, the determination of electroni ...

MINERALOGICAL SOC AMER2020

Dissolved major and trace geochemical dynamics in Antarctic lacustrine systems

Tyler Joe Kohler

Clearwater Mesa Uames Ross Island, northeast Antarctic Peninsula) provides a unique opportunity to study solute dynamics and geochemical weathering in the pristine lacustrine systems of a high latitude environment. In order to determine major controls on t ...

Elsevier2020

Mn4+-Substituted Li-Rich Li1.2Mn0.43+Mnx4+Ti0.4-xO2 Materials with High Energy Density

Chunyang Zhang

In this work, Li-rich Li1.2Mn0.43+Mnx4+Ti0.4-xO2 (LMMxTO, 0

2020

Phyllomanganate vein-infillings in faulted and Al-poor regoliths of the New Caledonian ophiolite: periodic and sequential crystallization of Ni-asbolane, Alk-birnessite and H-birnessite

Gabrielle Dublet

Mineralogy, chemistry and spatial distribution of phyllomanganates, found in abundance at the bottom of thick Ni-laterite deposits, were established on dislocated vein-infillings showing banded and fibrous patterns (i.e. colloforms with rows of tiny boxwor ...

2019

Plagioclase Glomerocrysts: taking the pulse of volcanic eruptions

Anders Meibom, Stéphane Laurent Escrig

Volcanic eruptions result from complex interplay of magmatic processes including the ascent and storage of magma in the crust, volatile exsolution and crystallization. The dynamics of crystallization in shallow subvolcanic systems and the consequences of i ...

2019

Investigation of subglacial weathering under the Greenland Ice Sheet using silicon isotopes

Tyler Joe Kohler

Subglacial chemical weathering plays a key role in global silicate weathering budgets, contributing to the cycling of silicon (Si) in terrestrial and marine systems and the potential drawdown of carbon dioxide from the atmosphere. Here, we use data from tw ...

2019

Performance of Limestone Calcined Clay Cement (LC3) with various kaolinite contents with respect to chloride transport

Karen Scrivener, François Henri Avet, Mohammadhadi Kazemi Kamyab, Hamed Maraghechi

The durability of mortar and paste mixtures with respect to chloride ion ingress was investigated for binary blends of Portland Cement Calcined Clay, and ternary systems of Limestone Calcined Clay Cement (LC3). Five clays from various sources with differen ...

SPRINGER2018

Effect of laser rescanning on the grain microstructure of a selective laser melted Al-Mg-Zr alloy

Christian Leinenbach

The microstructures of alloys created via Additive Manufacturing (AM) can vary substantially from those present in cast or wrought products, due to the very rapid solidification associated with AM. While numerous studies have investigated the process-micro ...

2018

The Effect of Alkali on the Properties of Limestone Calcined Clay Cement (LC3)

Karen Scrivener, Wilasinee Hanpongpun

The impact of alkali content on the properties of Limestone Calcined Clay Cement (LC3) was investigated in this study. KOH was added in order to increase the alkali content of the blended cements from 0.44% Na2Oeq to 1.21% Na2Oeq. The increase of alkali ac ...

Springer2018

Weekly to monthly time scale of melt inclusion entrapment prior to eruption recorded by phosphorus distribution in olivine from mid-ocean ridges

Anders Meibom, Stéphane Laurent Escrig, Lukas Baumgartner, Othmar Müntener

Melt inclusions (MIs) hosted in euhedral olivine have been proposed to represent droplets of primary melt, protected from processes occurring near Earth's surface during eruption. The complex zoning of phosphorus (P) in some olivines and the presence of a ...

Geological Soc Amer, Inc2017

A strategy for an accurate estimation of the basal permittivity in the Martian North Polar Layered Deposits

This paper deals with the investigation of the Mars subsurface by means of data collected by the Mars Advanced Radar for Subsurface and Ionosphere Sounding working at few megahertz frequencies. A data processing strategy, which combines a simple inversion ...

Wiley2017

The importance of mantle wedge heterogeneity to subduction zone magmatism and the origin of EM1

Stéphane Laurent Escrig

The composition of the convecting asthenospheric mantle that feeds the mantle wedge can be investigated via rear-arc lavas that have minimal slab influence. This "ambient mantle wedge" composition (the composition of the wedge prior to the addition of a sl ...

Elsevier2017

Short magmatic residence times of quartz phenocrysts in Patagonian rhyolites associated with Gondwana breakup

Anders Meibom, Stéphane Laurent Escrig, Lukas Baumgartner, Susanne Seitz

A key parameter in the study of magma evolution is the time scale on which magmatic processes occur. Using nanoscale secondary ion mass spectrometry (NanoSIMS), SIMS, and cathodoluminescence (CL) analyses, we have measured titanium (Ti) diffusion profiles ...

Geological Society of America2016

Multilevel and Local Timestepping Discontinuous Galerkin Methods for Magma Dynamics

Jan Sickmann Hesthaven

Discontinuous Galerkin (DG) method is presented for numerical modeling of melt migration in a chemically reactive and viscously deforming upwelling mantle column. DG methods for both advection and elliptic equations provide a robust and efficient solution ...

Springer2015

Composition of the core from gallium metal-silicate partitioning experiments

James Badro

Gallium concentration (normalized to CI chondrites) in the mantle is at the same level as that of lithophile elements with similar volatility, implying that there must be little to no gallium in Earth's core. Metal-silicate partitioning experiments, howeve ...

Elsevier2015

Infiltrated Cu8Al-Ti alumina composites

Andreas Mortensen

The effect of titanium additions on the interface and mechanical properties of infiltrated Cu8 wt%Al-Al2O3 composites containing 57 +/- 2 vol% ceramic are investigated, exploring two different Al2O3 particle types and four different Ti concentrations (0, 0 ...

Elsevier2014